Automated measurement of samples is important in a number of industries, such as the chemical and biotechnology industries, where the concentration of certain components of the sample is of interest. For example, quantification of biomolecules such as proteins and nucleic acids from patient samples is an important area of research and commercial development. Quantification of biomolecules and other types of samples is typically performed by optical measurements including fluorescence, luminescence, or relative light absorption. Portable solutions for these applications are a large and growing segment of the overall market.
Measurement systems typically shift a platform containing the sample to bring the sample in alignment with an optical detection unit, or vice versa. This may be achieved by either stopping the sample when in alignment with the optical detection unit and conducting the measurement, or synchronizing light detection with an actively moving sample. Synchronized detection may be cumbersome at high speeds, and typically requires positional sensors on the platform and a high quality motor with feedback mechanisms to maintain a constant shifting speed. Additionally, the time at which the optics are in alignment with the detection region is very brief, requiring a high intensity signal to achieve a favorable signal to noise ratio. Therefore, synchronized detection is typically reserved for high cost or low sensitivity systems.